Ceratopsids, or horned dinosaurs, are a group of large-bodied, quadruped herbivores that lived roughly 65-70 million years ago. Part of a larger group of dinosaurs that include stegosaurs, ankylosaurs, ornithopods, and pachycephalosaurs, the better known members of the ceratopsids include centrosaurs, chasmosaurs, and triceratopsians. All are easily distinguished by the horns and frills on their skulls; in fact, ceratopsids have among the largest, most elaborate skulls found in vertebrates. They were one of the most successful of all dinosaurs and their remains are well known from many locations in the United States, Canada, and Mexico. They died out at the end of the Cretaceous along with the rest of the dinosaurs.The outgrowth of the Royal Tyrrell Museum's Ceratopsian Symposium, this volume presents a broad range of cutting-edge research on the functional biology and behavior, systematics, paleoecology, and paleogeography of the horned dinosaurs, including descriptions of newly identified species. There is also a history of collecting these dinosaurs, plus a supplementary CD-ROM containing a history of ceratopsian discoveries in Canada and a list of the specimens recovered to date.